Fluid actuated feed engaging mechanism



May 29, 1934- R. M. GALLOWAY 1,960,699

FLUID ACTUATED FEED ENGAGING MECHANISM Filed May 16, 1931 3 Sheets-Sheet l INVENTOR BY ATTORNEY 77%) M ,LW

y 1934' R. M. GALLOWAY 1,960,699

FLUID ACTUATED FEED ENGAGING MECHANISM Filed May 16, 1951 3 Sheets-Sheet 2 1 /a T 0 *n 2/ 20 34 H l 25 25 q J 5' |l Z5 INVENTOR 22 BY ATTORNEY May 2 934- R. M. GALLOWAY FLUID ACTUATED FEED ENGAGING MECHANISM Filed May 16, 1931 3 Sheets-Sheet 3 //IIIIIIIIIIIIIIIIIIIIIII/ I115 Patented May 29, 1934 UNITED STATES FLUID ACTUA'IED FEED ENGAGING MECHANISM Robert M. Galloway, Richmond, Ind., assignor to The National Automatic Tool Company," Richmond, Ind., a corporation of Indiana Application May 16, 1931, Serial No. 537,897 4 Claims. (01.- 77-42) This invention relates to drilling machines or the like and is more particularly concerned with feed controlling mechanisms for such machines.

It has for a primary object to provide a ma- 5 chine tool with means permitting a rapid approach of the tool and work by hand and thereafter, without stopping the forward movement, to automatically engage the power feeding means at the proper time so as to check the relatively rapid movement and cause a feeding rate of movement to take place before the tool engages the work and to continue at this rate until the proper depth is reached.

A further object of this invention is to provide a single control wheel or lever which may be operated to bring the tool and work into close proximity and to then automatically engage the power feed for the tooling operation and to so arrange the parts that the throwing in of the power feed is resiliently accomplished thereby to prevent undue clashing of gears and thus prolong the life of the individual parts.

Still another concept of this invention is to provide a machine tool with means for automatically and mechanically engaging a power drive at a preselected point and arranged so that the power may thereafter be disengaged or suspended automatically at the proper point or at any time at the will of the operator, and the parts returned to their original positions.

In carrying out the objects mentioned herein and in accordance with this invention it is proposed to provide a machine tool, for example an upright drilling machine, with a translatable spindle which may be moved toward or away from the work by means of pilot wheel or hand wheel connected therewith. The mechanism is so designed that when the pilot wheel is operated through a given distance, the power feed is automatically thrown in and to thereby render the manual means ineffective. Heretofore, the operator was obliged to stop the rotation of the wheel and by means of an auxiliary lever, engage the power feed at the proper moment. This always has been an idle movement, requiring the whole attention of the operator and his two hands, and tends toward imperfect and slower work because of the inherent frailties of the ordinary workman.

This invention overcomes this undesirable condition by arranging a fluid operated feed engaging mechanism in a manner whereby the power feed will be automatically thrown into action when the tool spindle reaches a given position in its travel toward the work. In this way no tools or work-pieces can be damaged by too rapidengagement thereof and the capacity of the machine for producing finished work-pieces is ma terially increased.

Other objects and advantages will be in part indicated in the following description and in part rendered apparent therefrom in connection with the annexed drawings.

To enable others skilled in the art so fully to apprehend the underlying features hereof that they may embody the same in the various ways contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings, like characters of reference denote corresponding parts throughout all the views, of which:-

Figure l is a side view of a drilling machine depicting a preferred embodiment of this invention. Fig. 2 is an enlarged side view of the tool head, partly in section, illustrating the relative positions of portions of the feed mechanism. Fig. 3 is a rear view of the upper portions of the machine showing the air valve and its actuator. Fig. 4 is a sectional view along line 4-4 of Fig. 2 and illustrates the mounting of the feed worm. Figs. 5 and 6 are sectional views illustrating the power drive to the spindle and from the spindle to the feeding mechanism.

Fig. 1 illustrates a representative type of machine tool embodying this invention and which comprises a base member 1, an upright standard or column 2. A head member or gear box 3 is mounted upon the column and contains the usual feed and speed change gears for the spindle 4 which is also journaled therein. Power for driving the spindle 4 is derived from a motor 5, or other suitable source, and which through the change gears, indicated generally as 6, drives the spindle at a plurality of rates of speed.

The final gear of the speed train is secured to a sleeve-like member 7, splined or keyed to the spindle 4, and which carries at its upper end a bevel gear 8 from which the poweris taken for driving the power feed mechanism that effects translatory movement of the spindle.

The feed change gears, indicated generally as 9, and pick-off gears 9 are located in the feed box, the former of which are adapted to be shifted by lever 10 to one or more positions so as to effect a plurality of different rates of axial movement to the spindle for any given spindle speed. The final power feed to the spindle is accomplished through a worm shaft 11, worm gear 12, worm wheel 13 and feed shaft 14 to the spindle sleeve 17. A pinion 15, cut on the shaft 14, meshes with rack teeth 16 formed on the spindle sleeve 17, and when revolved by hand or power effects translation of the spindle toward or from the work.

The feed worm 12 may be referred to as the drop worm type and is journaled in a swinging bracket 18 that is pivoted at 19 in a portion of the frame. The worm is moved into and maintained in engagement with the worm wheel 13, by means of a cam or eccentric 20 which bears against a plate 21 secured to the underside of the swinging bracket 18, and elevates the same whenever the cam 20 is so actuated.

So that the feed may be thrown in at the proper time on each work-piece and so that the operator may have at least one hand free when starting the tooling operation to complete the setting up of the work-piece, ifnecessary, or to make adjustments of one kind or another means are provided for actuating the cam 20 automatically thereby to throw in the power feed just before the tool engages the work. Obviously, if the work 12 were brought positively into engagement with the worm wheel 13, ruination of the worm or wheel results, except in the remote possibility that the gear teeth being positioned so as to drop perfectly into mesh with each other at the moment of engagement. Too frequently the teeth of the gears hit on top of each other and prevent the engagement until one of the members has turned sufiiciently to clear. Therefore, to prevent damage to the parts while yet accomplishing the inter-engagement of teeth automatically, a fluid motor comprising a cylinder 23 and a fluid actuated piston 24 mounted adjacent the hand control lever 22 is provided.

The piston rod 25, when extended, engages a short lever 26 .secured to the cam shaft 2'7 and rocks the latter and the cam 20 to engage the power feed. Fluid pressure for urging the piston 24, and the parts associated therewith into operative relation, is controlled by a valve V, of a conventional design, which is actuated by trip dogs as will hereinafter appear.

Normally the valve assumes a closed position, that is, the pressure fluid is closed 01f, and the motor 20 is open to the exhaust. Under these conditions resilient means such as a spring 28 retracts the piston rod and maintains the same in an ineffective position.

The valve V is opened by means of a trip device including a bracket member 29 translatable with the spindle sleeve 1'7, and an adjustable rod 30. The depending portion of the pilot rod 30 is adapted to slide within a bearing 31 provided by the bracket 32 that supports the valve, and carries at one side thereof a trip pawl or dog 33.

As the spindle descends (under the action of the manual means) the rod 30 also descends and enters the bearing formed in the valve bracket. A small lever 34 that actuates the valve, projects into the path of movement of the dog 33 and is depressed thereby as the spindle descends and opens the valve. Fluid under pressure, preferably air, passes tothe feed gear actuating motor 20 and the worm gear is thereby urged into mesh with the worm wheel. Immediately the manual traverse stops and the spindle continues its downward movement at the feeding rate selected.

Pressure in the cylinder remains on until the trip dog 33 rides past the lever 34, which then springs back closing the valve and opening the cylinder 20 to the exhaust. It will be noted that the contour of the cam 20 is so formed as to maintain the drop worm in engagement with the Worm wheel even though the actuating pressure is released.

The spindle continues its downward feed until a boss 35, carried by the bracket 29 engages an adjustable dog 36 carried by a second trip rod 37. The lower end of the rod 37 engages the upper surface of the lever 26, and when urged downwardly by the descending bracket 29, rocks the cam 20 and releases the worm 12. The driver 12 immediately drops out of engagement with the worm wheel and the power drive is suspended.

The power drive being thus disconnected at the proper depth, the spindle is again free to move upwardly and does so under the action of a counterpulling mechanism such as the coiled spring 38. One end of the spring issecured to the elevating shaft 14 and the other end secured to a stationary portion of the frame or casing 39. As the spindle moves downwardly additional energy is stored in the spring suflicient to later elevate the spindle to its uppermost position. The tension of the spring may be easily varied to compensate for variations in the weight of the tools or fixtures attached to the spindle, by readjusting the casing 39 relative to the shaft 14.

During the return travel of the spindle the trip dog 33 again passes the valve lever 34 and so as to render the trip dog inoperative to again open the valve V and throw in the power feed, the dog 33 is pivotally mounted in a recess 40 formed in the guide bar 30 and disappears therein as it passes the valve lever.

The spindle continues its upward movement, under the action of the counterbalancing device, until the bracket 29 engages a collar 41 mounted upon the throw-out bar 3'7 and elevates the same until collar 42, adjustably mounted upon the lower end of the bar 37, engages a stationary abutment 43 which limits and stops further upward movement of the spindle 4.

In certain adaptations of this invention it may be desirable to have a two-way acting valve tripping dog thereby to render the machine continuous in its operation, however, in this application of the invention a one-way acting spring pressed trip dog is to be preferred in order that the spindle return rapidly its full distance and stop, thereby to give the operator whatever time is needed to change work-pieces or make adjustments.

Manual rapid traverse of the spindle is effected through the medium of a large hand wheel or pilot wheel 44 secured to the pinion shaft 14, and by reason of its large diameter a minimum amount of effort need be expended in bringing the spindle to the work or to the point at which the power feed is engaged.

It is sometimes desirable also to have means for feeding the spindle manuaily, as for example when setting up the machine before running a group of similar work-pieces, and to this end, a hand wheel 45 is mounted upon a projecting end of the worm shaft 11. When the feed change gears 9 are positioned in an intermediate or neutral position, and lever 22 or the valve V actuated so as to engage the worm 12 with the worm wheel 13, the hand wheel 45 may be operated manually to efiect an accurate or as fine a feed to a given depth as may be desired. The various trip dogs may then be set in place so that subsequent operation of the machine will be controlled automatically as heretofore explained.

Once the machine is set up, all that the operator is required to do is to clamp the work-pieces in place and turn the hand wheel 44 unti1 the power feed automatically engages. Thereafter the cycle of operation is entirely automatic and requiring no further attention on the part of the operator. The translation of the spindle may be reversed at any time during the cycle and caused to be retracted, by swinging the feed cam lever 22 toward the front of the machine. The worm gear thereupon drops out of engagement of its own weight, assisted however in this action also by the driving pressures between the teeth of the gears, and the spindle recedes out of the way.

Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specific aspects of this invention and, therefore, such adaptationsshould be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent of United States:-

1. A power feed control mechanism for a machine tool having a member to be translated combining, a feed shaft operatively connected with said member; manual and power operated means selectively operable to drive said member, said power means including a gear on the feed shaft and a laterally movable driving gear adapted to be engaged therewith, said driving gear being journaled in a swinging bracket and normally maintained out of engagement with the gear on the feed shaft by the force of gravity; a cam member for moving and maintaining said driving gear in engagement with the gear on the feed shaft; power actuated means including a fluid motor controlled by an instrumentality carried by said translatable member for moving said cam to an effective position thereby establishing a driving connection between said gears; means actuated by the movement of said translatable member for moving said cam member to an ineffective position; and manually operable means operative independently of said two last mentioned means for controlling the positioning of said cam member.

2. In a drilling machine having a translatable spindle the combination of a manually operable lever normally operative to translate said spindle in a forward direction; power means for imparting feed movements to said spindle including a driving and a driven-gear, said gears being relatively movable and normally disengaged from each other; power means for moving and maintaining said gears in driving engagement with each other, comprising a gear engaging eccentric, an air actuated motor for moving said eccentric to an effective position, andvalve means for controlling the action of said motor;

a one way acting trip dog carried by said spindle for actuating said valve means thereby to effect engagement of said gears when said spindle reaches a predetermined position in its travel under the action of said manually operable lever; auxiliary trip mechanism actuated by said spindle for moving said eccentric to an ineffective position when the spindle reaches a predetermined position under the action of said power means; and a manually operable control lever for moving said eccentric to an efiective or ineffective position independently of said air motor and trip mechanism.

3. An automatic power actuated feed control device for an upright drilling machine having a translatable spindle comprising a spindle feed shaft; a manually operable lever connected therewith and normally operative to effect translation of said spindle in a forward direction; power means for imparting feed movements to said spindle at a predetermined rate comprising a driven gear on said feed shaft and a driving gear movable into driving relation therewith, said driving gear being normally disengaged from said driven gear and inoperative to feed the spindle; power means for engaging the said gears, comprising a gear engaging cam, a

fluid actuated motor for moving said cam to a position establishing a driving connection between said gears, and valve means for controlling the action of said motor; a valve actuating element movable with said spindle for actuating said valve means thereby to effect engagement of said gears when the spindle has been moved to a predetermined position by said manually' operable lever; and means actuated by said spindle for moving said cam to an ineffective position thereby to disengage the power feed means when the spindle reaches a predetermined further position in its travel.

4. A drilling machine combining a translatable spindle; a feed shaft and a lever connected therewith normally operative to translate said spindle manually; .a gear on said shaft; power means selectively operable to translate said sp ndle including a driving gear normally disengaged from the gear on said shaft; power means for moving said driving gear into driving relation with the gear on said feed shaft comprising a cam member, an air actuated piston for moving said cam and thereby said driving gear to an effective position, and an air valve for controlling the movement of said piston; a one way acting trip dog carried by the spindle for actuating said valve when the spindle has been moved to a predetermined position under the action of said manual means thereby to render the manual means inefiective and the power means operative to continue the translation of said spindle; and trip mechanism adapted to be actuated by said spindle at the end of a predetermined further movement thereof for moving said cam member to an ineffective position to effect disengagement of said gears.

ROBERT M. GALLOWAY. 

